The ISL97631 represents a high efficiency, constant frequency PWM regulator with integrated boost diode and FET. Designed for use in white LED driving applications, the ISL97631 features efficiencies up to 85%. It operates at 1.35MHz switching frequency and operates from an input voltage of between 2.7V and 5.5V. The maximum output voltage of 27V enables the ISL97631 to drive up to 6 LEDs in series. It is also possible to use the ISL97631 to drive LEDs in series/parallel combination for applications requiring up to 15 LEDs.